... to the creation of the hole results in local overstressing of the rock and the formation of zone of yielded rock or a breakout. The resulting stress distribution, in turn, depends upon the absence or presence of local weaknesses SUchas fissures, joints or bedding planes. Studies by Kwong and Kaiser (1989...

... the accuracy of back-calculated rock mass deformation properties be improved (Kaiser and Mackay, 1982). This paper presents briefly two field instrumentation studies and discusses problems related to the data interpretation. Factors affecting the selection of the best location for positioning stress change...

...), Wawersik (1973) and da Fontoura (1980). Most of the existent data are based on creep tests performed on relatively intact rock. Exceptions are Lama (1974) and Kaiser and Morgenstern (1979) who present qualitative information on the time dependent behavior of jointed rock-like material. The present paper...